The Hemingses of Monticello: An American FamilyBy Annette Gordon-ReedNorton, 798 pp., illustrated, $35

Whatever its eventual outcome, the 2008 presidential campaign obviously marks a new racial moment in the United States. Yet older politics of race linger in many forms. Ironically, one prominent recent victim is Barack Obama's current opponent, John McCain, who was the subject of rumors spread by Bush supporters in South Carolina during the 2000 primaries that he was the father of an illegitimate black child. Such tactics date back to the early days of the Republic, most famously to claims about Thomas Jefferson's sexual involvement with slave women, particularly Sally Hemings, and the fathering of "Negro" offspring circulated by Federalist Party enemies.

Unlike the case with McCain, however, these claims about Jefferson were largely true. While for many years most historians and biographers of Jefferson rejected the notion of an intimate sexual relationship between Jefferson and Hemings, recent research and DNA analysis have created a consensus among scholars about the great probability of a nearly four-decades-long union and four children who survived into adulthood. Perhaps the most groundbreaking of that newer scholarship was Annette Gordon-Reed's 1997 "Thomas Jefferson and Sally Hemings: An American Controversy." While Gordon-Reed did not claim that the relationship between the two was beyond doubt, she used her training as a lawyer and a scholar to build a case that such a relationship was probable.

As the subtitle suggests, Gordon-Reed's new book, "The Hemingses of Monticello: An American Family," can be seen as a sort of sequel to her earlier work. It seeks with considerable success to place Hemings and her family at the center. As Gordon-Reed points out in the first chapter, few even of those accounts that admit the union and shared family of Hemings and Jefferson as a near certainty treat Hemings as a person with any intrinsic historical importance or as a member of a family that stretched before and beyond the life of the famous American Founder. It also makes a powerful argument for the historical significance of the Hemings family not only for its engagement with a principal architect of the early Republic, but also for the ways the family embodies the complexities and contradictions of slavery in the United States.

Sally Hemings's mother, Elizabeth Hemings, was the child of an African mother and an English father. Elizabeth in turn became the longtime slave and mistress of John Wayles, Jefferson's father-in-law. Jefferson's wife, Martha, was Sally Hemings's half sister - though Hemings entered Jefferson's life in a major way only when he was consul to France after Martha's death. While legally "Negroes" and slaves, both the "black" siblings of Martha Jefferson and the children fathered by Jefferson with Hemings received special opportunities, affection, and recognition from Jefferson.

One of the challenges that Gordon-Reed faced in writing is that the character, thoughts, and even appearance of Hemings remain largely opaque. It is not entirely clear, for example, why she and her brother Robert chose not to appeal to France's "Freedom Principle," in which slaves attain freedom once they set foot in the country - though Gordon-Reed speculates perceptively about why they did not. Yet through a thorough consideration of evidence and sharp deduction, a portrait emerges of a very young pregnant slave woman who was careful and canny enough to successfully gain a commitment to ultimately free any offspring resulting from her union with Jefferson. We also see her as a middle-aged woman sentimental enough to keep small personal items of Jefferson's as mementos after his death, whether or not she actually loved Jefferson in a way that we would recognize now.

A related challenge is that the figure of Jefferson threatens to obscure any attempt to bring the Hemingses to the fore. This challenge Gordon-Reed only partially surmounts. Of course, Jefferson was part of the family. Also, as Gordon-Reed reminds us, the life and, especially, the death of male slave owners were of the greatest consequence for slave families. While, for example, the Hemingses were able to remain largely intact, at least initially, because of their special relation to Jefferson, who left his estate virtually penniless at his death, other families at Monticello were broken up and sold off. Such traumatic separations were endemic to a labor system where individuals were fungible commodities. And even the Hemings family was ultimately fractured as three of Hemings's children "passed" into the white population and one remained "Negro."

"The Hemingses of Monticello" has much to say about the nature and practice of slavery in the United States. Jefferson doubted the morality of the slave system. Yet the building and running of his dream estate of Monticello depended on slave labor. Despite his doubts, slavery was, as Gordon-Reed points out, convenient for Jefferson. Obviously acquiescence in such a convenient (for the master), if morally troubling, labor arrangement can be extrapolated far beyond Jefferson to the nation as a whole. Similarly, the complex entanglements of the Hemingses, the Wayles, and the Jeffersons, in which ties of blood and affection were partially, if not publicly, acknowledged and yet undermined, corrupted, and hidden by the system, speak volumes about the vexed intertwining of slave and master, of "black" and "white" in the larger society. Finally, Gordon-Reed tells the story of an American family whose members were determined to play the cards they were dealt so as to affirm their human dignity and to allow the greatest opportunities to socially advance - two imperatives that did not coexist easily under slavery.

James Smethurst teaches in the W.E.B. Du Bois Department of Afro-American Studies at the University of Massachusetts at Amherst.